The Rebel Yells were the 1st BKPs I owned that I didn't gel with pretty much instantly.
There was always something a bit wrong with the sound of them to my ears and I've been on the verge of swapping them out a few times. I've just put the guitar they're in, Japanese Tokai Love Rock, in Eb tuning and strung it with 11s and the RYs are pretty much perfect for me now. They're bright enough to cut through a band, but not too bright like they were in standard, and just seem to work in a slightly lower tuning.
As for BKP addiction I have 17 guitars: 15 with BKPs, 1 (2 if I win something I'm looking at) with Dimarzios and 1 with Seymour Duncans.
Although saying that I'm pretty sure going forwards that any new guitars I get won't be getting BKPs as apart from the Emeralds I've got all the models that appeal to me. BKP looks to be going into more of a 'modern/alternative' direction with the extended range guitars and pickups, which is cool if you're into that stuff and that style of instrument but as I'm not, I'll have to find alternatives.
But all my guitars that currently have BKPs will ALWAYS have BKPs in them as I've found 15 or so sets that really work for me :lol: